Drain Vokera Excel 29 boiler

[thejinkazama]

Hello,

I have a Vokera Excel 29 gas boiler which is losing pressure. I need to drain the boiler in order to repressurise the expansion vessel back to 1 bar. Can anyone explain how to drain this boiler?

Thanks

[Someone-Else]

You don't usually drain the boiler. Are you sure its the expansion vessel at fault? Did water come out of it when you tested it?

As for draining the system look for the lowest point and look for a "drain cock"

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Looks like the one above. You put a hose on it and open the square nut.

[aeromech3]

The manual does mention the boiler drain valve, see page 5, Fig 4 item #2; in other models this is mentioned as a red knob; it is likely next to the safety valve relief pipe which leads to the outside property safety vent.
https://manualzz.com/doc/54104151/voker ... uctions#p6

[thejinkazama]

There’s no air inside the expansion tank. I can’t repressurise it with a pump as there’s water in it so I’m trying to drain the water out.

Thanks for the info regarding the drain valve. How does it work? I know it can be turned but don’t see where the water inside the boiler would drain to.

[Someone-Else]

If there is water in the expansion cylinder, you are wasting your time. The expansion cylinder is a cylinder (or circle, some are almost square) with a "balloon" in it. If the balloon gets punctured, it lets water in. It needs to be replaced, or another one added.

[aeromech3]

If you just want to lower the boiler water pressure, then the knob can be turned and I am guessing the water will drain via the relief valve pipe to the outside.
If there is water on the air side of the expansion tank then this is a fault as S-E states and unlikely to drain out by the above method.
Perhaps you should explain the fault you have more precisely?